Aqueous dispersion of vinyl chloride polymer containing substituted polyacrylamide



United States Patent AQUEOUS DISPERSION or "VINYL CHLORIDE POLYMER-CONTAINING SUBSTITUTED POLY- ACRYLAMIDE Richariiiwfhhariesiand William H. 'McKnight, Pittshurgh, 1a,, assignors ,to' Union Carbide Corporation, a corporation of New York DrawinglA l plication November 30, 1953 Serial No. 395,277

1' 7 Claims. (Cl. 260-295) tiles and paper and for preparing films either by casting' or dipping Highly plasticized compositions may be handled in paste form, but compositions low in plasticizer must be dissolved in solvents or dispersed as organosols in non-solvents to attain the fluidity required for application. x The flammability of these compositions limits ,their usefulness. It would be desirable to sub- 2,914,498 Patented Nov. 24, 1959 coating thus rendering them less water soluble, or they stitute water as the dispersing medium, particularly since these resin:polymers may be manufactured as latices.

To attain adequate stability for shipment, storage and coating, however, such latices require the addition of a water soluble thickener. Conventional thickeners used 1 in aqueous dispersions are starch, gum arabic, casein, polyvinyl alcohol, .polyacrylic acid, carboxymethyl cellulose; hydroxy ethyl cellulose and the like. None of these form achomogeneous film with vinyl chloride polymers and copolymers. ity the film is degraded in physical properties and the resistance to "water-is; decreased because of the water solub' i'naterials in the film,- This has limited the use.

of aqueous dispersions" of vinyl Polymers as coating mpositions I V V :1 objeigiovf this invention to provide water soluble' thickening agents suitable for controlling the vis-' cosity and the spreading and penetrating properties of the resins mentioned -above :when these resins are dispersed in vvater. for use as coating composition or as compositions for dipping and casting. Itis a further object of the invention to provide such thickening agents may be protected by being dissolved in the water resistant vinyl resin. The exact mechanism of their beneficial effect has not been fully established.

We have also found that by the use of these polyacrylamides the viscosity. of aqueous compositions of vinyl polymers can be readily controlled, thereby regulating their stability for shipment and storageor their spreading and penetrative properties when used for coat ing paper, textiles, or as casting or dipping compositions:

Thepolyacrylamides which we have found particularly suitable are the poly N,N, alkyl substituted acrylamides. 'These compounds are polymers of compounds havingthe general structure; 7

where R or R can be an alkyl radical of one to three carbon atoms. They includethe- ,dimethyl, diethyl; di-

propyl and methylethylcompounds. These N,N alkyl acrylamides can be prepared by an. exchange reaction between an alkyl secondary amineand an acrylate ester,-

according'to the following equationr OHFCHCONRRHI- can on Polymerization: may be carried'out inwater solution at temperatures of about'30. C. 'using a catalystsuch as potassiumi persulfate; Aqueous polymer concentrations of 755-10 percent are preferably employed having a viscosity ofiabout. 20,000-50,000' c.p.s. Brookfield vis- As a result of this incompatibilwhich will also promote the cohesive properties of films ofthese resins during" drying and thereby afford more latitudepin the drying and baking schedules during film formation. .Yet another object of the invention is to provide water soluble thickening agents which will be compatible with the water-dispersed phase of the resin so as to permit preparation of a homogeneous film.

We have now found that those water soluble polymers belonging to the class of compounds described as polyacrylamides are particularly suitable for use as thickeners in aqueous dispersions of vinyl poly'mers- These polyacrylamides we have found are readily compatible with the aforementionedvinyl polymers. Moreover, they retain this compatibility in both theair dried and baked Consequently, the films deposited from compositions containing this novel thickener are homogeneous and coherent fuse to clear films when baked. Moreover, such coatings have been found to be more moisture resistant than films deposited from compositions" using the converitional' water soluble thickening agents. This maybe due to the fact that these polyacrylamides undergo further polymerization during the baking of the" cosity at6r.p.m. a

The resins used in our compositions are principally vinyl resins, such aspolyvinyl chloride, polyvinyl acetate or'the copolymersxontaifiingfrom to percent polymerized'vinyl chloride and from 15 to 0 percent of eopolymerized vinyl acetate. Aqueous dispersions '.of these resins maybe prepared in a number of ways. For example, the vinyl monomers may be polymerized directlyin water suspension using appropriate polymerization catalysts. -.The polyacrylamide thickener 'may be? added to stabilize thesellatices either during production or added after the vinyl polymer has been formed.- Or

the "Y latex may be feyvfiri tt ad ubse u n f redisper'sedfin water; The "polyacrylamide. thickener has 1 been found useful in the processofredispersing the vinyl polymer aswll as thickening the dispersion; prepared without it. Another way to prepare the aqueous dispersion' of the"'vin yl polymer is todisperse the vinyl resin in a solvent along with a suitable emulsifying agent such as an alkyl arylpolyether alcohol and then slowly addwater with'good agitation in an amount suflicient to give'a latex of the desired consistency.-

The' polyacrylamide thickener has been advantageously employed with other latices "such as the latexpf 'a c0n-' joint polymer of vinyl chloride and vinylidene' chloride, or With mixtures of polyvinyl chloride latex and butadiene-acrylonitrile polymer latex.

The composition may include emulsion stabilizers,

The amount ofthickener ?to be used in .the'coniposi tion is minor and willdepend to some extent on the conf sistency of the latex andcnthe concient'ration'and cam sistency of the thickener, Generally speaking 0.5, to 3 parts ofuhickener by dry weight are, used 'forkeach 100 parts, of resin dispersed in the. 'v vater' depending upon the viscosity required.

Formulations containing these polyacrylamides as thickeners can be used for a variety of purposes. Used for cloth coatings they impart to the cloth a smooth surface and an excellent soft hand. They adhere well and have good moisture resistance. They may heapplied directly to the cloth or over a priming coat. They alsomay be used forthe preparation of emulsions having a high percentage of lacquer phase. Such emulsions are relatively more stable on storage than emulsions prepared Without the polyacrylamides. These novel formulations are also useful in the preparation of dipping hydrosols for the manufacture of dipped goods such as gloves. When used for cloth coating they can be applied on the conventional cloth coaters and then baked at temperatures of 32535 0 F. Used as a dipped coating they usually require a prebake at lower temperatures of about 200 F. and then a final bake at 350 F. The formula tions may be used for the preparation of cloth laminates. When so used there is no penetration of the resin to the outer cloth and a strong laminar bond is formed.

The following examples are typical of the invention.

Example I 7 Parts by weight Vinyl resin (vinyl chloride (97% )-vinyl acetate The vinyl resin, plasticizer, emulsifier, stabilizer, pigments and filler were milled together for about one-half hour to give a somewhat damp powder mix. The acrylamide thickener and water were added to form a thick paste which was passed through a 3 roll' paint mill to give a composition of smooth texture and good cohesiveness. This compositions was coated onto cloth using a conventional doctor blade cloth coater and gave a smooth. even film which, when baked at temperatures of about 325 to 350 F. for from 3 to 5 minutes, was smooth and tough and adhered well to the cloth.

Example II Parts by weight Vinyl resin (vinyl chloride 97% vinyl acetate (3%) copolymer) 37.0 Plasticizer (di 2-ethyl hexyl phthalate) 18.0 Water 45.0

% poly N,N dimethyl acrylamide in aqueous solu-;

tion V 1.8

I Example Ill Parts by weight Vinyl chloride-vinylidene chloride copolymer latex (50% resin content70% vinyl chloride) 100 Poly N,N dimethyl acrylamide aqueous solution' (6% resin content) The above components were mixed to givea stable latex which when used to coat a glass plate gave a good clearfilm when baked at 350 F. for three minutes.

Example IV Parts by weight Vinyl resin (vinyl chloride (97%) vinyl acetate The vinyl resin was dissolved in the ketone-toluene mixture, the plasticizer and pigments added and then the whole was slowly added with good agitation to the water, wetting agent, and polyacrylamide. A stable oil in Water emulsion was formed at 63% lacquer phase and with 37% water phase which was stable on storage. When the above procedure was followed except for omitting the polyacrylamide, an emulsion did not form until the water' phase was 54% and then it was not as stable as the emulsion containing the polyacrylamide.

Example V Parts by Weight A B C D E Vinyl Resin (Polyvinyl chloride) Platst)icizer (Di 2-ethy1 hexyl phth l a e Filler (Calcium carbonate) Pigment (Titanium oxid Emulsifier (Alkyl-aryl polyether alco 1 1. 1 1 1 Stabilizer (Glycidyl ether of Bisphenol A) 2 2 2 2 2 Poly, N,N dimethyl acryl a 6.0% aqueous solution 13. 3 26. 6 39.9 Poly, N,N dimethyl acryl amide 7.5% aqueous solution 33. 2 49. 8 Water 100. 7 87. 4 74. 1 81. 8 64. 2 Percent Dry Poly N,N dimethyl acrylamide based on resin 1 2 3 2 3 The above formulations were prepared similar to that described in Example I. All coated well on the conventional doctor blade coater and gave a smooth, tough film when baked at temperatures of 325 -350 F. for from 3 to 5 minutes. Samples exposed in the humidity box at a relative humidity of 100 percent for 24 hours showed good adhesion.

Example VI This experiment compares the formulation using polyacrylamides as a thickening agent in combination with other conventional thickening agents.

Parts by Weight Vinyl Resin (Polyvinyl chloride) 200 200 200 200 Plasticizer (Di-2-ethyl hcxyl phthalate) 130 130 130 Filler (Calcium carbonate) 60 60 60 60 Pigment (Titanium dioxide) 30 30 30 30 Emulsifier (Alkyl aryl polyether alcohol) 2 2 2 2 Stabilizer (Glycidyl ether of Bisphenol A)- 4 4 4 4 Poly N ,N dimethyl acrylamide 7.5% concentration aqueous solution 58. 4 26. 7 26. 7 26. 7 Oarboxy methyl cellulose 3% concentration aqueous solution 66,.7 Acrylic copolymer 15% concentration aqueous olu n 13. 4 Hydroxy ethyl cellulose 2. O W er 174. 8 34. 6 87. 9 99. 3 Percent Thickener (dry) based on resin-- 2 2 2 2 All of these coating formulations were prepared according to the directions of Example I and all gave smooth pastes. All were applied to cloth on a conventional cloth coater.

Coating A spread well and gave a smooth film. Coating B spread welland gave a smooth; film'with good hardness. Coating C spread about as well as B but film was not as smooth. Coating D was borderline in coating properties. a

The coated cloth was baked for 3% minutes at 350 F. Coating A gave good adhesion and tough film. Coating B gave poor adhesion and poor toughness. Coating C gave fair adhesion and good toughness. Coating D gave poor adhesion and poor toughness f Allof these cloths were soaked overnight in water. The cloth coated with Coating A showed the best retention of adhesion and toughness. v j v These tests showed that the coating on the cloth with the formulation containing only poly N,N dimethyl acryl amide was superior in adhesion, toughness and moisture resistance.

Example VII A comparison of coating formulations containing poly N,N dimethyl acrylamide as thickener and one containing sodium carboxy methyl cellulose as thickener was made with the following results; The formulations were prepared as described in Example I and contained the following.

Parts by Weight Vinyl Resin Plastioiym Filler 60 60 Pigment. 30 30 Stabilizer 4 Fh'nnlsifier 2 2 Oarboxy methyl cellulose (solid) 2 Poly N,N dimethyl acrylamide 5% concentration aqueous solution- Water 230 6 Example IX A e This example illustrates a formulation which can be applied to a textile material for the purpose of making a laminate. 1 a

Parts by weight Vinyl resin 22.7 Plasticizer I 9.0 Poly N,N dimethyl acrylamide 6% concentration aqueous solution 3.8 Mineral wax 0.2 Water 64.3

' the gabardine cloth, a stiffened laminate was formed in each case, with no penetration of the resin to the outer cloth surface. The laminar bonds were strong.

What is claimed is:

1. A resinous film-forming composition comprising an aqueous dispersion of a vinyl chloride polymer selected ride containing a predominant amount of vinyl chloride- Adhesion of formulation A was degraded upon pressing in a hydraulic press, whereas with formulation B the adhesion to the cloth improved when pressed under the same conditions.

Example VIII This is an example of a dipping formulation prepared by using poly N,N dimethyl acrylamide as a thickener.

Parts by weight Vinyl resin (vinyl chloride (97)-vinyl acetate (3%) copolymer) 33.9 Plasticizer (di-Z-ethyl hexyl phthalate) 17.0 Mineral wax 0.3 Stabilizer (phosphated castor oil) 0.3 Poly N,N dimethyl acrylamide (dry) 0.3 Water 48.2

from the group consisting of polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate containing at least by weight of vinyl chloride polymerized there in, and copolymers of vinyl chloride and vinylidene chlopolymerized therein, and, per parts by weight of said vinyl polymer, up to 3 parts by dry weight of a water soluble polymer of an N,N dialkyl-substituted acrylamide having the structure:

if oHFoH,-(JN

R! wherein R and R each represent an alkyl group having up to three carbon atoms, said composition being characterized by the ability to form a homogeneous single phase dry film.

2. A resinous film-forming composition comprising an aqueous dispersion of a vinyl chloride polymer selectedfrom the group consisting of polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate containing at least 85 by weight of vinyl chloride polymerized therein, and copolymers of vinyl chloride and vinylidene chloride containing a predominant amount of vinyl chloride polymerized therein, and, per 100 par-ts by weight of said vinyl polymer, from 0.5 to 3 parts by dry weight of a water soluble polymer of an N,N dialkyl-substituted acrylamide having the structure:

0 R H CHg=CH2C-N R! wherein R and R each represent an alkyl group having up to three carbon atoms, said composition being characterized by the ability to form a homogeneous single phase dry film.

3. A resinous film-forming composition comprising an aqueous dispersion of a vinyl-chloride-vinylidene chloride copolymer containing a predominant amount of vinyl chloride polymerized therein and, per 100 parts by weight of said copolymer, up to 3 parts by dry Weight of a water soluble polymer of an N,N dialkyl-substituted acrylamide having the structure:

. 7 acterized by the ability to form a homogeneous single phase dry film. l

4. A resinous film-forming, composition comprising an aqueous dispersion of a vinyl chloride-vinyl acetate copolymer containing at least 85% by Weight of vinyl chloride polymerized therein and, per 100 parts by weight of said copolymer, up, to 3 parts by dry weight of a Water soluble polymer of an N,N dialkyl-substituted acrylamide having the structure:

wherein R and R each represent an alkyl group having up to three carbon atoms, said composition being characterized by the ability to form a homogeneous single phase dry film.

5. A resinous film-forming composition comprising an aqueous dispersion of a vinyl chloride polymer selected from the group consisting of polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate containing at least 85% by weight of vinyl chloride polymerized therein, and copolymers of vinyl chloride and vinylidene chloride containing a predominant amount of vinyl chloride polymerized therein, and, per 100 parts by weight of said vinyl chloride polymer up to 3 parts by dry weight of poly N,N dimethyl acrylamide, said composition being characterized by the ability to form a homogeneous single phase dry film.

aqueous dispersion of a vinyl "chloride-vinylidene chlon'de c'opolymer containing a predominant amount of vinyl chloride polymerized therein, and, per 100 parts by weight of said copolymer, up to 3 parts by dry Weight of poly N,N dime'thyl acrylaniidq said composition being charaoterized by the ability to form a homogeneous single pha's'eldry'film.

' 7. A resinous film-forming composition comprising an aqueous dispersion of a vinyl chloride-vinyl acetate copolymer containing at least by weight of vinyl chloride polymerizedtherein, and, per parts by weight of said copolymer, up to 3 parts by dry Weight of poly N,N dimethylacrylamide, said composition being characterized by the ability to form a homogeneous single phase dry film.

References Cited in the file of this patent UNITED STATES PATENTS 1,976,679 Fikentscher et a1. Oct. 9, 1934 2,123,599 Finkentscher et a1. July 12, 1938 2,311,548 Jacobson et al Feb. 16, 1943 2,598,663 Kropa June 3, 1952 2,620,324 Coover et a1 Dec. 2, 1952 2,632,704 Lowe et al Mar. 24, 1953 OTHER REFERENCES Rinse: Paint Technology, February 1952, pages 56- 58, volume 17, No. 194.

Parker: Ofiicial Digest, October 1952, pages 700-709. 

1. A RESINOUS FILM-FORMING COMPOSITION COMPRISING AN AQUEOUS DISPERSION OF A VINYL CHLORIDE POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYVINYL CHLORIDE, COPOLYMERS OF VINYL CHLORIDE AND VINYL ACETATE CONTAINING AT LEAST 85% BY WEIGHT OF VINYL CHLORIDE POLYMERIZED THEREIN, AND COPOLYMERS OF VINYL CHLORIDE POLYMERIZED THERERIDE CONTAINING A PREDOMINANT AMOUNT OF VINYL CHLORIDE POLYMERIZED THEREIN, AND, PER 100 PARTS BY WEIGHT OF SAID VINYL POLYMER, UP TO 3 PARTS BY DRY WEIGHT OF A WATER SOLUBLE POLYMER OF AN N,N DIALKYL-SUBSTITUTED ACRYLAMIDE HAVING THE STRUCTURE: 